Only add the errorInterceptor to the main logger (#925)

There are no error objects in stat logger meta that need rewriting.

Author: gigabo

packages/react-server/core/logging/server.js

@@ -35,7 +35,10 @@ var makeLogger = function(group, opts){
 
 	logger.setLevels(config.levels);
 
-	logger.rewriters.push(errorInterceptor);
+	// Only need to look for errors in the main logger's meta.
+	if (group === "main") {
+		logger.rewriters.push(errorInterceptor);
+	}
 
 	logger.stack = common.stack;